Abstract

We report the structure, thermal and magnetic properties of a non-equilibrium Al_0.6(Fe_50Cu_50)_0.4 alloy powder produced by rod milling and chemical leaching. An X-ray diffractometry(XRD), a transmission electron microscope(TEM), a differential scanning calorimeter(DSC), a vibrating sample magnetometer(VSM), and superconducting quantum interference device(SQUID) were utilized to characterize the as-milled and leaching specimens. The crystallite size reached a value of about 8.82 nm. In the DSC experiment, the peak temperatures and crystallization temperatures decreased with increasing milling time. The activation energy of crystallization is 200.5 kJ/mole for as-milled alloy powder. The intensities of the XRD peaks of as-milled powders associated with the bcc type Al_0.5Fe_0.5 structure formative at 350°C sharply increase with increasing annealing temperature. Above 400°C, peaks alloted to Al_0.5Fe_0.5 and Al_5Fe_2 are observed. After annealing at 600°C for 1h, the leached Ll specimen transformed into bcc alpha-Fe and fcc Cu phases, accompanied by a change in the structural and magnetic properties. The saturation magnetization decreased with increasing milling time, and a value of about 8.42 emu/g was reached at 500 h of milling. The coercivity reached a maximum value of about 142.7 Oe after 500 h of milling. The magnetization of leached specimens as function of fields were higher at 5 K, and increased more sharply at 5 K than at 100 K.

• Keywords: Rod milling;Chemical leaching;Activation energy;Magnetization;